"That is happiness; to be disolved into something complete and great. When it comes to one, it comes as naturally as sleep." - Willa Cather

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Tuesday, 22 March 2011

A cautionary tale and injury prevention for the pregnant runner

When I said I would write my next blog post about injury prevention in pregnant running, I didn't know it would be clouded by such a serious occurrence. No, luckily I have not gotten injured yet, but for those of you who don't read Stefanie Schocke's blog (and I hope she doesn't mind I mention this!), she has just learned that she suffered a stress fracture at the inferior pubic ramus at the end of her pregnancy. She has really been an inspiration to me, with how fast she ran pregnant (made a habit of setting PR's) and how she almost made it to the end before any injury set in. But her injury makes me realize how serious, relevant and poorly understood this topic is among pregnant runners.

I also didn't know when I said I'd write this post that the incidence of pelvic/hip/groin injury was so common in pregnant runners )you are, of course, all smart enough to take a poll on my blog with a grain of salt - but it's hard not to find it a little interesting).

You are more likely than not to have your running curtailed by an injury while pregnant. And the most likely injury (67%) is of the pelvis.

And I consider any groin, hip or pelvic injury to be equivalent. They all occur in the above ring and occur by the same basic mechanism: the uneven loosening of/stress on the pelvis.

What I am about to write is simply an amalgamation of what I have learned in medical school and years of reading about running and pregnancy and is not from any particular research, though I quote one study. The only good reason you have to read it is you probably won't be able to find much else written on this topic (if you do, let me know! I want to read it.).

So, let's get started with my interpretation of the biomechanics that predispose to pelvic injury:

1. The belly grows, of course. This changes the body's position while running. Initially I thought if one ran with a backpack that one would balance out "the problem", but this is the opposite of the truth. (yes, this is my very own illustration)

The truth is, the larger the belly grows, the more a woman leans back to compensate. This puts stress on the sacroiliac joint and the back of the pelvis.

2. At the same time, the ligaments loosen in the pelvis in response to the hormone relaxin. This makes good sense for pushing a baby through. But when things loosen, they unfortunately tend to loosen unevenly.

So what to do to protect the pregnant pelvis while running?

First, buy shoes that promote running on the forefoot. This will give you a posture where you are leaning more forward and less stress with be placed on the pelvis and SI joint this way. If you already run with vibrams or barefoot, you really can't do anything more in this department.

I have now taught myself to run in shoes with very minimal cushion with more of a forward-leaning style. My feet and calves have taken a beating. And it was a while before I could run 3 hours straight in these shoes, but yesterday I did 3 1/2 hours and it went well. I will add that running on dirt as opposed to asphalt makes transition to this running style a lot easier.

Second, you need to have balance in the strength of the muslces that support and surround the pelvis. The balance of strength is perhaps equally important to strength itself when preventing uneven loosening of the pelvis. So what do I recommend? Well, if you run, you legs are strong, but you need to strengthen your abs, back, inner and outer thighs, butt and even upper body to balance things out. Remember this is all theory.

My favorite exercises involve the exercise ball and I attend classes where we focus on the entire body and core. It is easy to overdo the abs and forget the inner and outer thighs for example. Balancing acts (which I have perfected while waiting for trains with my backpack on) are great for strengthening our neglected deep core muscles.

Now, the topic that gets everybody's undies in a bundle: weight gain. It seems intuitive that the less weight one adds to the pelvis, the less chance one has of injuring the pelvis. And I think this is generally true that women who gain less tend to be able to run longer while pregnant. It is very simple mechanics of course, though there are always confounding factors involved.

But, but, but, but. And I admit this actually occurred to me in the last week: women who are pregnant are in essence amenorrheic. They don't have the cyclical estrogen and progesterone spikes that keep female bones strong. Not only this (here comes the one study), but increased prolactin levels cause decreased bone mineral density. Black et al. (J Bone Miner Res 2000; 15:557-63) showed an average decrease in bone mineral density in the spine of 3.5% in 10 women over the course of their pregnancies. First of all, it is thus important to get adequate calcium and vitamin D. But another thing that keeps bones strong is a little extra weight. It is therefore, in theory, important to gain ENOUGH weight so our bones don't weaken too much. (just as an aside, I would love to do a study taking serial dexa scans of women to see if there is a correlation between weight gain while pregnant and the development of osteopenia - or fractures for that matter.).

20 comments:

I think another helpful tool while running pregnant is a support belt. It can really help take the pressure of your big belly of of your pelvic and groin areas, not to mention your bladder! They are great for anyone experiencing back pain too. I kind of see it as a sports bra for my pregnant stomach. I had to try a few different ones and different positions to get it right, but when I did, I loved it!

as a physical therapist, i disagree with making a blanket recommendation that a newly pregnant runner should all the sudden change shoe types and attempt to change one's gait pattern... it may have worked for you, but it's a recipe for disaster for most women... especially pregnant women. If you're interested in changing footwear and/or gait pattern, this should ideally be something you work on when all else is "normal" for you... without adding in the hormones, weight changes, ligamentous changes, etc.

I think far more impt to avoiding injury during pregnancy (while running or staying active) is the nutrition side, strength training, and LISTENING TO YOUR BODY! it's rare that the body that's feeling completely "normal" and painfree just POPS out a stress fracture... usually, there's some ache, some discomfort, some "niggles" that have come on... and the person chooses to run through them thinking it's all good... this is true for tendonitis, stress fx, and anything other overuse unjury when we're NOT pregnant as well. we get away from it sometimes, but when we have this growing being inside that takes everything from our bodies FIRST and leaves us with what's left, it's imperative that we listen to our bodies... and have a good PT nearby to help us when we don't. ;)

I would also caution about switching to minimalist shoes. While there is a lot of anecdotal warning, I was shown recently actual numbers that show an increase in the frequency of 2nd metatarsal stress fractures -- a link directly correlating with the timeline of the increase in popularity of Vibrams and other "minimalist" footwear. Not everyone, sure. But with added weight and the other factors you mention, I can't help but fear that pregnant women would be more at risk for these "barefoot" injuries.

Grace - I have heard a lot of good things about support belts, though have never tried one. Thanks for mentioning them.

Hey kzpt,

Thanks for commenting from a physical therapist point of view. I had read that pregnant women were advised against running barefoot pregnant. My thoughts on minimalist shoes and vibrams and barefoot is one needs to make the transition gradually whether pregnant or not. I knew it was my strategy for avoiding injury even before I got pregnant, so have gradually worked up to where I am now. We'll see if I last longer than 26 weeks before a major hip injury this time!

I had a stress fracture years before I got pregnant in my pelvis that happeneded COMPLETELY out of the blue - I had NEVER had pain there before that very day. And if I understood correctly, Stefanie's happened out of the blue. And the one case report I read of a post-partum pelvic fracture also happened out of the blue without any pain beforehad. I take it as a GOOD sign that I have twinges of pain in my hip once in a while; I figures that means less of a chance for a big injury like last time.

Green Light, good point about the stress fractures. I hadn't read that, though I would imagine they occur because of switching to barefoot or vibrams too quickly and running on paved surfaces (as opposed to trails). But it's a good thing to bring up considering the apparent increased risk of fx in pregnancy.

Some day I'll be on topic, but I just went to the hairfinder site you used for a previous post... and I'm laughing my ass off at the men's hairstyles. The site should be named "guys who got beaten up in high school!" All that's missing is the Flock of Seagulls fiasco hair. How could anyone compile so many hideous photos???

Well, for me even running forward enough so that it's midfoot was a big change. It's simply an experiment that I hope works. Last time I only made it to week 26 before trouble set in and I just want to last longer.

Every woman simply has to find what works for her. What I wrote about is simply my plan and I'm sticking to it, that is unless it doesn't work.

Steve Q, I love hearing that I had some part in you laughing so hard, but I'm just not sure which site you're talking about!!

Completely agree with you about the stress fracture showing up out of NOWHERE!!!! It was like I got stabbed in the groin, no signs. Yes, I had some pubic symphysis issues during pregnancy, but there was no reason to stop running. Looking into the vitamin D/calcium deficiency.

Stefanie - thanks for the comment :). Glad you at least agree with the pain part ;). I was really worried about how exactly to write about your fracture. I hope you know I'm simply looking at it scientifically and not in any way criticizing you. I wish you a fast, fast, fast recovery!!!

Kirsten, you know, I actually read that Dena Kastor GAVE UP running while pregnant and I was really miffed! But you know, we all have to do what we are comfortable with. BUT STILLL...

Steve, yeah, Amy Sproston is one of my best friends who I have never met :). Though we ARE going to meet when she visits family in Madison. She found my blog through Olga's, if I remember correctly. I like how you said we girls stick together. It's a happy truth - we crazy running women need each other.

Hey there. I had two stress-fractures -- one in each pubic ramus -- the year after I had my son. I had a Dexa-Scan about a year after that (2010), and it was normal (and I had one in 2006, and it was still normal). I'm just saying this because you wondered what they would show Here is your sample of 1. ;-) I also nursed my son for 14 months and then had another baby. So, two pregnancies, and while breastfeeding, and still had normal density. I also gained very little weight with both pregnancies. Yet, still normal bone density.

Jacqueline, Good point. You don't have to have abnormal bone density to get stress fractures. There were stress fractures found randomly in something like 2% of Israeli army recruits (who were men with presumably normal bone density). I think there are actually a lot of stress fractures that are never found. But on the other hand, if bone scans are used, they are also overdiagnosed. It's an interesting topic that I wish I knew more about. But one seeming certainty is the less you weigh, the more likely you are to get a fracture (this was also true among the Israeli soldiers).

That's interesting on the weight comment. And just want to also say, my body is obsessed with ovulation, ha ha, so everything returns to normal, for me, pretty quickly post-partum, so no issues there. I think for me, the injury really was pure overtraining. It hurts to admit that. ;-)

I will say that the stress fractures to pubic ramus hurt like hell and suck more than any other injury I've had. I wouldn't wish them on anyone. They are so weird.

Hello from Rude Skov

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My name is Tracy. I am a physician scientist from the USA, living with my husband and two young boys in Denmark. I work as a post-doc fellow at Næstved Hospital. I have a scientific interest in vision loss, vision loss during exercise, exercise, running during pregnancy, MAF training as well as nutrition and health for athletes. I also have a love for music, physics, statistics, cycling, yoga, cross-country skiing, bla bla bal.

I was a member of Team USA at the IAU World Championships in Ultra Trail Running in 2013 in Wales. I am now training to run with Team Denmark at the IAU World Championships in Annency, France in May 2015.